WHO issued a stiff warning to Covid-skeptics who have been saying that in the absence of a vaccine, policies that let the SARS-CoV-2 virus spread freely would lead to eventual “herd immunity” , and that might be preferable to continued containment and social-distancing measures. 

“Herd immunity is a concept used for vaccination, in which a population can be protected from a certain virus if a threshold of vaccination is reached, for example, that immunity against measles requires about 95% of the population to be vaccinated,” said WHO Director General Dr  Tedros Adhanom Ghebreyesus at a press briefing on Monday.   

“Never in the history of public health has herd immunity been used as a strategy for responding to an outbreak, let alone a pandemic. It is scientifically and ethically problematic,” added the WHO Director General.

He cited the lack of information about the strength and duration of any acquired immunity as being other big unknowns. 

And at best only about 10% of the global population has been infected so far with COVID-19, meaning that 90% remain uninfected and vulnerable to both the short-term risks as well as a range of emerging long-term impacts – which are still only emerging.  

“The vast majority of people in most countries remain susceptible to [COVID-19] virus,” he said.  “It is unknown how long this immunity lasts, or how strong it will end up being. Letting COVID-19 circulate would lead to unnecessary infections, suffering, and death.”

Added Maria Van Kerkhove, WHO health emergencies technical lead, not only may acquired immunity after recovering from COVID-19 prove to be more transient than might be assumed, but the long-term effects of of the virus, even on mildly ill people, remains an open question: 

 “We are only now starting to really learn about the long term impacts on the heart on the brain on the lungs on mental health on people’s ability to to recover from COVID infection,” she said (See related story). “ And so not only do we need to work very hard at reducing mortality, and we are seeing the benefits of that we still need to reduce the numbers of infections that we are seeing.”

She stressed that the estimated infection mortality rate – that is the number of deaths in comparison not the actual degree of infection in the population – reported and unreported – is hovering around .6% – which is still six times higher than seasonal flu.  And those rates increase with age as well as in people with pre-existing infections.

Big Rise in Reported COVID-19 Cases Worldwide

The WHO officials spoke as the world continued to chalk up record increases in the number of reported new COVID-19 infections for the fourth day in a row – with numbers soaring, particularly in Europe and the Americas. Although infections in hard-hit Brazil now appear to be plateauing, those in Mexico and the USA have continued to rise. 

On Friday, the WHO announced a new high of daily COVID-19 cases worldwide, with over 350,000 reported infections, and that peak has been exceeded every day since then. The global total number of COVID-19 cases has now risen to over 37 million, with over one million deaths. 

“Around the world, we’re now seeing an increase in the number of reported cases of COVID-19, especially in Europe and the Americas,” said Dr Tedros. “Many cities and countries are also reporting an increase in hospitalizations and intensive care but at the same time, we must remember that this is an uneven pandemic countries have responded differently, and countries have been affected differently. 

Despite those increases, only an estimated 10% or less of the world’s population has been exposed to the SARS-CoV-2 virus that causes COVID, said Kerkhove, citing the pooled results of some 150 serological and epidemiological studies that have been conducted so far worldwide.

“So the world is still susceptible,” Van Kerkhove said, adding that WHO is now working with some 50 countries to provide an even more robust method for conducting such studies and pooling their results.

Not a choice between letting virus run free or shutting down 

However, with new outbreaks across Europe bringing record daily infections, populations also are showing greater resistance to renewed estrictions. Public health officials cite pandemic fatigue and a lack of public trust in health systems and governmental institutions as posing major challenges to national efforts to curb the spread of COVID-19.  

Dr Tedros urged countries to continue relying upon tried and tested tools, such as testing, isolating cases, quarantining contacts, use of masks and hygiene measures – as well as encouraging people to avoid crowds and closed settings, wherever possible. 

“It’s not a choice between letting the virus run free, and shutting down our societies.” said the WHO Director General. “This virus transmits mainly between close contacts and close outbreaks that may be controlled by implementing target measures. Prevent amplifying events, protect the vulnerable. Empower, educate and engage communities, and persist with the same tools that we have been advocating since day one. Find, isolate, test and care for cases, then test and quarantine their contacts. This is what countries are proving works.” 

The WHO officials stressed that disinfection strategies and hand hygiene also remain extremely important, particularly in light of the recent findings by Australia’s national science agency, CSIRO,  on the persistence of SARS-COV-2 virus on glass, stainless steel, plastic, and paper banknotes. The study found that the virus can survive for up to 28 days at 20 C° and 24 hours at 40 C° – although Van Kerkhove noted that the study was conducted with high virus concentrations in dark, contained settings – while sunlight and other factors in the natural environment may break down viral components more rapidly.  

The fact some countries, such as Spain may be seeing a surge in COVID-19 cases without the huge mortality impacts of the “first wave” in the spring, is testimony to the fact that the “clinical care is improving” and the world is “getting better at preventing outbreaks from happening,” said Health Emergencies Executive Director Mike Ryan. But he and Kerkhove both warned against complacency saying that right now, new infections in many European countries appear to be more concentrated among young people who have fewer underlying conditions. But even so, if infection rates are left to spin out of control, that could be “catastrophic” for older and more vulnerable groups.

WHO Advice For US President Donald Trump?  – ‘CDC Has Its Own Guidance’

Asked to comment about the controversy surrounding President Trump’s decision to hit the presidential campaign trail again,  even before he has produced a negative COVID-19 test following recovery from his infection, the WHO officials refrained from offering advice to the US President – at least explicitly.  

“I am not going to give specific advice about individuals,” said Ryan. “But what we can say is that the US public health services have very clear criteria in place for what represents the release of an individual from what might be isolation.

“From WHO’s perspective, we allow both testing and duration of the number since the onset of symptoms, both approaches are offered to our Members States as mechanisms,” he added, saying that the duration of the isiolation should be counted as “Ten days from the onset of symptoms, plus three days from the … cessation of the last symptoms. And again, all countries have adapted that according to their national protocols, and therefore we will not comment on whether any specific individual meets the requirements of their national protocol.”

Image Credits: NIH Image Gallery, R Santos/HP Watch, Johns Hopkins University.